These Blood Suckers Cost $2.5 Billion to $138 Billion Each Year

Three guesses on which blood suckers are costing the world somewhere between $2.5 billion to $138 billion each year. Vampires? Well, the Twilight novel and movie series portrays vampires as a bit more “emo” and “preppy” than vicious. How about vampires? No, there have been limited vampire economic studies. Vampires? No, repeating the same guess won’t make it correct.

The answer is hookworms. The numbers come from our study, which quantified the economic burden of this blood-sucking parasite across different countries and was just published in PLOS Neglected Tropical Diseases. Currently, hookworm affects approximately over 500 million people around the world (the Centers for Disease Control and Prevention (CDC) says an estimated 576-740 million people), and 5.1 billion remain at risk for getting infected. Why the range of costs? Well, every year is different and the bottom end of the range may be a very, very conservative underestimate.

Yes, hookworms suck…in many ways. They do not make good pets, roommates or party guests. Hookworms bear some resemblance to the “graboids” in the movie Tremors (you know the movie with Kevin Bacon in it). There are differences in appearance, and hookworms are much, much smaller (usually less than 1 cm long). Here’s an Animal Planet segment on hookworms:

Also, the life cycle of hookworms is different and a little more similar to the Alien movie series. Hookworms live in moist soil in warmer areas. After hookworm eggs hatch in the dirt, the larvae can burrow into your skin. For example, if you walk barefoot on soil with hookworm larvae, they may enter through your feet. The larvae then continue to burrow into your blood vessels and then ride your blood to your lungs. Then they move up your lungs through your windpipe into your throat. You then swallow the worms so that they go down into your intestines. They then lodge their mouths onto the walls of your intestines and begin sucking your blood, which they can do for years. While in your intestines, they also lay eggs (up to 30,000 per day), which can produce more hookworms. Your poop then contains hookworm eggs, which can lead to hookworm larvae that can infect others.

Here’s more trouble. People often do not know that they are infected with hookworms. You may not see blood or eggs in your stool. The steady blood sucking may make you feel weaker, more tired or abdominal pain or have difficulty thinking but these symptoms develop slowly and insidiously. Many people with hookworm infection never even see a doctor.